ECIS 2002 • June 6–8, Gdańsk, Poland — First — Previous — Next — Last — Contents — 840 EVOLUTION IN THE ONTOLOGY-BASED KNOWLEDGE MANAGEMENT SYSTEMS Nenad Stojanovic Institute AIFB - University of Karlsruhe, Germany +49 721 608 7363 nst@aifb.uni-karlsruhe.de Ljiljana Stojanovic FZI Research Center for Information Technologies at the University of Karlsruhe, Germany +49 721 9654 804 Ljiljana.Stojanovic@fzi.de Siegfried Handschuh Institute AIFB - University of Karlsruhe, Germany +49 721 608 6554 sha@aifb.uni-karlsruhe.de ABSTRACT An ontology-based knowledge management system uses an ontology to represent explicit specification of a business domain and to serve as a backbone for providing and searching for knowledge sources. But, dynamically changing business environment implies changes in the conceptualisation of a business domain that are reflected on the underlying domain ontologies. Consequently, these changes have effects on the performance and validity of the KM system. In this paper we make an analysis of the problems induced by using not-evolved ontologies and present an approach for enabling consistency of the description of knowledge sources in an ontology-based KM system in the case of changes in the domain ontology. This approach is based on our research on ontology evolution and ontology-based annotation of documents. The proposed method is implemented in our semantic annotation framework so that efficient acquiring and maintaining of ontology-based metadata is supported. 1. INTRODUCTION Ontology-based knowledge management systems represent a class of KM systems that are centred on an explicit conceptualisation of a domain model, so called domain ontology [Gr93]. This ontology provides semantic means for structuring knowledge repository, which enables more effective providing and searching for knowledge in a knowledge management system. For example, a content of a knowledge sources can be described using some controlled domain vocabulary constrained by the set of assumptions about intended meaning of used terms. That is inherently provided by using an ontology and the underlying process is called semantic annotation [Ha01]. In that way, when one